As a TNFR-Fc fusion protein in which a ligand binding part of a human p75 TNF-α receptor (TNFR, TNF-α receptor) is linked to an Fc fragment of human IgG1, Etanercept was released by Amgen under the trade name of Enbrel in 2002. Etanercept competitively inhibits in vivo binding between TNF-α receptors on the surface of a cell, thereby inhibiting a TNF-α-related immune response. Accordingly, as a TNF-α inhibitor, Etanercept is used for rheumatoid arthritis, psoriasis, ankylosing spondylitis, etc., and clinical studies for its application to vasculitis, Alzheimer's disease, and Crohn's disease are in progress.
Meanwhile, a gene recombinant pharmaceutical product is a pharmaceutical product containing a peptide, a protein, etc., produced by using a genetic manipulation technique as an active ingredient. Use of biotechnology is advantageous in that it is possible to obtain a large number of highly pure recombinant proteins which are difficult to obtain in a natural state, but an expression structure itself may be unstable since a gene of a target protein is inserted into a host cell from outside. Besides, proteins are produced by expressing the gene in a microorganism or a cell of an animal or plant, but not in the human body, the recombinant proteins may be different from native proteins in terms of structural, physicochemical, immunochemical, and biological properties or features (Kwon, et al., FDC Legislation Research V, vol. 1, 2, 13-21, 2010).
In particular, in the case of a glycoprotein, glycosylation and a structure or form of a glycoform (sugar chain) may differ according to a culture condition. In other words, in the process of glycoprotein production, difference in glycoform structures or the amounts of saccharides constituting the glycoform structure lead to various types of glycoforms, thereby causing heterogeneity according to differences in production conditions. In the case of glycoproteins with different glycoform structures, they are different from native forms in terms of in vivo movement or tissue distribution, or are antagonistic to the native forms, causing an adverse reaction. When administered continuously for a long period of time, they act as antigens and may cause an immunological problem.
As described above, as the glycoforms may become an important factor that may affect a pharmaceutical effect and in vivo movement, controlling the glycoprotein structures is very important in the field of development of recombinant glycoprotein products for medicines and development of mass production technology.
In this regard, Korean Patent Publication No. 2011-0139292, as a prior art, discloses control of protein glycosylation and compositions and methods related thereto, and Korean Patent Publication No. 2012-0134116 discloses a method for increasing N-glycosylation site occupancy on therapeutic glycoproteins.